The great Indigo glossary thread..

[benn]

Feel free to add your own:

albedo: Colour. The spectrum that is most reflected by the material (the rest of the wavelength is absorbed).

(ahem)

[PureSpider]

On Phong:
Phong Material: Reflective material, like porcelain or car paint or simple plastics or a mirror
IOR: How reflective the material is
Exponent: How sharp the reflection is, 1000000 is said to be a perfect mirror, 0 is diffuse.

Diffuse Material: A rough material without sharp reflections, clay is a good example of this.

[benn]

Oren-nayer: An extremely rough material that scatters light in every direction. Clay is a good example of this.

Sub surface scattering (SSS): A material that allows light to travel through it some distance before it is reflected. The light may bounce around inside the material for a long time, or exit back into the scene.

KD Tree: An acceleration structure used internally by Indigo that divides the scene into many small boxes so that it can rendered faster.

UV set: A list of coordinates that specify how a 2 dimensional texture is mapped onto a 3 dimensional object.

[Silmä]

Wiki-site: a way better way of doing this.

No, but seriously. A good wiki-documentation site would be great thing to have, as there's lots of random bits and pieces of information and tips and tutorials and stuff about indigo here on the forums. Having them all in one well interlinked site would help users to find and share information a lot easier than using the forum.

[Phoenix]

Wiki-site: a way better way of doing this.

No, but seriously. A good wiki-documentation site would be great thing to have, as there's lots of random bits and pieces of information and tips and tutorials and stuff about indigo here on the forums. Having them all in one well interlinked site would help users to find and share information a lot easier than using the forum.

A hell of +1!

[Borgleader]

On Phong:
Phong Material: Reflective material, like porcelain or car paint or simple plastics or a mirror
IOR: How reflective the material is
Exponent: How sharp the reflection is, 1000000 is said to be a perfect mirror, 0 is diffuse.

Diffuse Material: A rough material without sharp reflections, clay is a good example of this.

your IOR definition is quite wrong.

Source

The refractive index (or index of refraction) of a medium is a measure of how much the speed of light (or other waves such as sound waves) is reduced inside the medium. For example, typical soda-lime glass has a refractive index close to 1.5, which means that in glass, light travels at 1 / 1.5 = 2/3 the speed of light in a vacuum. Two common properties of glass and other transparent materials are directly related to their refractive index. First, light rays change direction when they cross the interface from air to the material, an effect that is used in lenses. Second, light reflects partially from surfaces that have a refractive index different from that of their surroundings.

I'll admit (and it's included in the definition) that some light does reflect but it's a minute percentage. I think the important concept about IOR is how it affects the direction of light.

[benn]

.pigm: Packed indigo material. A set of xml files and textures that are zipped up and have the .zip extension changed to .pigm.

[PureSpider]

@ Borg: I know that, thats why I wrote "On Phong:"
On opaque materials, the refraction doesn't matter, does it?
So it effectively IS the amount of light reflected on phong materials.

[Borgleader]

@ Borg: I know that, thats why I wrote "On Phong:"
On opaque materials, the refraction doesn't matter, does it?
So it effectively IS the amount of light reflected on phong materials.

Oh i thought you just repeated yourself for no reason

[pixie]

@ Borg: I know that, thats why I wrote "On Phong:"
On opaque materials, the refraction doesn't matter, does it?
So it effectively IS the amount of light reflected on phong materials.

From my understanding, ior in phong is bit like the ior behaves in water, after a given amount it turns opaque and all its left is pure reflection.

ior

ior.png (7.51 KiB) Viewed 2673 times

Discarding the transparency and focusing only on reflection we'll that with lower ior we'll have an angle threshold from no matter how high the exponent is it never be reflected, the smaller the ior is, the bigger this threshold will be.